System for assisting an operator in exerting efforts

ABSTRACT

A system for assisting an operator in exerting efforts comprises a garment that can be worn by the operator, which is to engage, when worn, the mutually mobile parts of a joint of the operator. The system defines at least one axis of rotation that is to assume a position corresponding to the joint of the operator. A device is carried by the garment and designed to operate so as to compensate the resistive moments that act on the joint during the effort exerted by the operator. A compensation device is provided equipped with a rotational assembly, which has a neutral position and is able to determine a pre-set plot of the assisting torque that is a function of the angle of rotation of the joint. The compensation device may include a tension regulation device to regulate a moment obtained about the joint of the operator.

FIELD OF ART

The system relates to passive assistive exoskeletons arranged to reducethe physical effort of operators.

BACKGROUND

The disclosure relates to a system for assisting an operator in exertingefforts, of the system comprising a garment that can be worn by theoperator, and which is configured to engage, when worn, the mutuallymobile parts of a joint of the operator and which defines at least oneaxis of rotation to assume a position corresponding to the joint of theoperator; and a device carried by the garment and designed to operate tocompensate the resistive moments that act on the joint during the effortexerted by the operator.

A device of the type referred to is described in the document No.WO2012/099995A2.

The known system referred to is designed for vertical support of thearms of an operator to assist him in tasks to be performed in positionswhere his arms are raised.

For this purpose, the system of the disclosure comprises supports forthe arms, and elastic means coupled thereto and operating for partiallycompensating the force of gravity acting on the operator's arms. Thesystem comprises articulated joints, which connect the supports of thearms to the harness worn on the torso of the operator to allow an—albeitlimited—freedom of movement for the arms, more particularly at theshoulder joints.

SUMMARY

Embodiments of the system of the disclosure relate to a passiveexoskeleton for relieving a load on a joint, for example, a shoulder,and for providing assistive effort. The object of the present disclosureis to provide an improvement over the prior art solution discussedabove, in particular from the standpoints of ergonomics and convenienceof use.

Specifically, the embodiments of the system rely on the principle of apassive assistive exoskeleton having an elastic mechanism arranged togenerate a torque proportional to the elevational angle of a joint, suchas an operator's arm. According to the embodiments, the elasticmechanism is configured to modify a distance between two extremities ofthe elastic mechanism to pre-tension the elastic mechanism among aplurality of predetermined tension settings, and as a consequence alevel of assistance provided by the exoskeleton. As an example, theelastic mechanism may be spring-based including at least one elasticspring element.

According to an embodiment, a system for assisting an operator inexerting efforts comprises a garment that can be worn by the operator,which engages, when worn, the mutually mobile parts of a joint of theoperator, and has a mobile frame that defines at least one axis ofrotation, which assumes a position corresponding to the joint of theoperator; and a compensation device carried by the garment and operableto compensate resistive moments acting on the joint during the effortexerted by the operator.

The compensation device comprises a first rotatable member and a secondrotatable member, which are connected together and are brought intorelative motion about a first axis of rotation because of the movementof the joint of the operator's body, wherein the second rotatable membercan rotate about a second axis of rotation; and an elastic mechanismhaving at least one elastic element, arranged for acting on the secondrotatable member to impart on the first axis of rotation a momentopposite to the resistive moments. The first and second rotatablemembers and the elastic mechanism are mutually prearranged in such a waythat, in at least one pre-set position of the joint, the force exertedby the elastic mechanism on the second rotatable member is oriented in adirection incident to the second axis of rotation of the secondrotatable member.

The mobile frame may comprise a first portion and a second portion whichare mutually mobile about the first axis of rotation.

The first rotatable member may be a gear wheel, fixedly mounted on thefirst portion and aligned with the first axis of rotation. The secondrotatable member is a gear wheel, fixedly mounted on the second portion,and rotatable about the second axis of rotation and mobile according toa motion of revolution about the axis of rotation. The elastic mechanismengages the second rotatable member, exerting a linear force on aneccentric point of the second rotatable member.

In another embodiment of the system of the disclosure, the compensationdevice may include an epicyclic gear train mounted at the first axis ofrotation and prearranged so a crown wheel of the gear train is fixedlymounted on the second portion and a central gear wheel of the gear trainis fixedly mounted on the first portion, or vice versa. The crown wheelor gear wheel define the first gear member or a third gear member. Thesecond rotatable member may include a planetary-gear carrier. Theelastic assembly engages the planetary-gear carrier, exerting a linearforce on an eccentric point thereof.

The elastic mechanism may comprise a battery of springs such that asecond end of the elastic mechanism is adjustable for setting thepre-tensioning of the elastic mechanism. The battery of springs may beconnected to first and second brackets, wherein the first bracket ismounted on the eccentric point of the second rotatable member, and asecond bracket is mounted on the second portion.

A tension regulation device may be connected and adapted to regulatetension in the elastic mechanism. The tension regulation device isarranged for pre-tensioning the elastic mechanism at a plurality ofdiscrete tension settings, and for placing the pre-tension at one of theplurality of discrete tension settings. The tension regulation devicemay include a cam assembly for adjusting the elastic mechanism at theplurality of discrete tension settings. The tension regulation devicemay include an interface mechanism allowing the operator to selectivelyadjust the compensation device.

The system may be designed for a shoulder joint of the operator, whereinthe pre-set position corresponds to a position of the arm extendingalong the operator's side. The first and second rotatable members maydefine a motion-transmission ratio defined because the elastic mechanismdetermines, on the first axis of rotation, a maximum moment in theposition of the arm projected forwards at 90°. The first and secondrotatable members may have a transmission ratio that is variable as afunction of the angle of rotation about the first axis of rotation.

The garment may comprise a portion designed to engage the torso of theoperator, and has a linear guide on which a sliding-block assemblyslides; a first articulation element, rotatably mounted on thesliding-block assembly about at least one second axis of rotation; and asecond articulation element, which is rotatably mounted on the firstelement, about the first axis of rotation. The first articulationelement may be connected to the sliding-block assembly through a jointwith two degrees of freedom, which defines a second axis of rotation anda third axis of rotation, orthogonal to one another.

The system may be adapted to the hip joint of the operator, wherein thepre-set position corresponds to an upright position of the operator.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the invention will emergeclearly from the ensuing description referring to the annexed drawings,which are provided purely by way of non-limiting example and in which:

FIG. 1 illustrates the system described herein in one embodiment, wornby an operator, illustrated in a front axonometric view.

FIG. 2 illustrates the system of FIG. 1 according to a lateral view.

FIG. 3 illustrates the system of FIG. 1 according to a rear view.

FIG. 4 illustrates the system of FIG. 1 according to a top plan view.

FIG. 5A illustrates internally, in an axonometric view, the compensationdevice of the system of FIG. 1 according to a first embodiment.

FIG. 5B illustrates internally, in an axonometric view, the compensationdevice of the system of FIG. 1 according to a further embodiment.

FIGS. 6A-6C illustrate diagrams provided by way of example of operationof the compensation device described.

FIG. 7 illustrates various examples of curves of the assisting torquethat can be supplied by the system.

FIG. 8 illustrates an embodiment of the system in perspective viewdescribed herein for application to the hip joint.

FIG. 9 illustrates an embodiment of the system in perspective viewdescribed herein for application to the knee joint.

FIG. 10 illustrates internally the compensation device of the system ofFIG. 1 according to yet a further embodiment.

FIG. 11 illustrates a further example of curve of the assisting torquethat can be supplied by the system.

FIG. 12 illustrates another embodiment of a compensation device for thesystem of FIG. 1 .

FIG. 13A illustrates an adjustment mechanism for the compensation deviceof FIG. 12 .

FIG. 13B illustrates the adjustment device of FIG. 13A without ameasurement scale and exposes a cam assembly.

FIG. 14A illustrates the cam assembly of FIG. 12 and the settingsthereof with the pin in a seated position.

FIG. 14B illustrates the cam assembly of FIG. 14A in a transitionalposition.

FIG. 15A illustrates the cam assembly of FIG. 14 in a third setting.

FIG. 15B illustrates the cam assembly of FIG. 14A in a seventh setting.

FIG. 16A illustrates a graph showing torque on a regulation positionversus cam rotation angle.

FIG. 16B illustrates a graph showing elastic potential energy versus camrotation angle.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

A better understanding of different embodiments of the disclosure may behad from the following description read in conjunction with theaccompanying drawings in which like reference characters refer to likeelements.

While the disclosure is susceptible to various modifications andalternative constructions, certain illustrative embodiments are shown inthe drawings and are described below in detail. It should be understood,however, there is no intention to limit the disclosure to the specificembodiments disclosed, but on the contrary, the intention is to coverall modifications, alternative constructions, combinations, andequivalents falling within the spirit and scope of the disclosure.

The references used herein are provided merely for convenience and hencedo not define the sphere of protection or the scope of the embodiments.

The system described is a system for assisting an operator in exertingefforts, of the type comprising:

-   -   a garment that can be worn by the operator, which is to engage,        when worn, the mutually mobile parts of a joint of the operator        and which defines at least one axis of rotation to assume a        position corresponding to the joint; and    -   a device carried by the garment and designed to operate to        compensate the resistive moments that act on the joint during        the effort exerted by the operator.

The system described herein has been devised with reference toapplications for assisting the operator in efforts involving theshoulder joint. As seen in what follows, the same principles set forthmay be applied also for systems for assisting the operator in effortsinvolving other joint groups or other joints, such as the hip joint orthe knee joint.

The system described herein is characterized in that the compensationdevice comprises:

-   -   a first gear member and a second gear member, which are        connected and are brought into relative motion about the        aforesaid axis of rotation because of the movement of the joint        of the operator's body, wherein the second gear member is        rotatable about its own axis; and    -   an assembly equipped with one or more elastic elements, which is        prearranged for acting on the second gear member to impart on        the axis of rotation a moment opposite to the resistive moments;    -   wherein the first and second gear members and the assembly are        mutually prearranged in such a way that, in at least one pre-set        position of the joint, the force exerted by the assembly on the        second member is oriented in a direction incident regarding the        axis of rotation of the second member.

In the pre-set position referred to above, the aforesaid assembly cannotimpart any moment of compensation on the axis of rotation of the system.

The aforesaid pre-set position hence corresponds to a neutral positionof the system, in which the operator receives no impulse on the joint.

Preferably, in the application to the shoulder joint, theabove-mentioned neutral position is made to correspond to the positionof the arms extending along the torso. In the application to the hipjoint, the neutral position is made, instead, to correspond to theupright position of the operator.

The present applicant has found that the possibility for the system toidentify such a neutral position constitutes a fundamentalcharacteristic for guaranteeing adequate comfort for the operator, aboveall for the person who, wearing the system, must perform a range oftasks not all linked, for example, to raising of the arms.

The system described herein is hence suited for constituting anaccessory that can be worn by the operator for the entire workshift,with the convenience for the operator to put it on just once whengetting dressed at the start of the shift.

Once again in the perspective of improving the comfort for the operator,in various preferred embodiments, the elastic mechanism of the system isprovided with a system for adjustment of pre-tensioning of the elasticmechanism, to enable the operator to choose assistance that he desiresor, possibly, to even exclude the assistance altogether, for exampleduring a prolonged pause from the workshift.

As will be seen in what follows, in various preferred embodiments, thesystem described has a system of axes of movement, which can assist andfollow in a precise and fluid way practically all the movements of thejoint and of the possible joint group or girdle to which the jointbelongs.

This system of axes of movement has proven to render the system ofassistance optimal from the ergonomic standpoint, and increase furtherthe perception of comfort by the operator.

With reference now to the figures, the system for assisting an operatorin exerting efforts represented therein, designated by the referencenumber 10, is particularly designed in the illustrated embodiment forassisting an operator in exerting efforts involving the shoulder joint.

The system 10 comprises a garment 12, which can be worn by the operatorand constitutes an item of clothing. Referring to the embodiment ofFIGS. 1 to 4 , the garment 12 has form and wearability like those of ajacket.

Preferably, the garment 12 is made of fabric, whether natural orsynthetic, and is possibly padded in some areas, for example in theareas of the trapezius, of the arms, and/or of the sides of theoperator. Once again, the garment 12 preferably englobes rigid orsemi-rigid elements (e.g. plates, bars), which contact the body of theoperator and, in view of this purpose, are shaped in a way correspondingto the shape of the area of the body of the operator which they are tocontact. These rigid or semi-rigid elements have the function ofdischarging the forces generated at the assisted axis on the operator'sbody, on specific parts thereof such as the shoulders and the pelvis,and in a distributed way to prevent excessive pressures that might betroublesome.

Applied on the garment 12 is a mobile frame designed to define theassisted axis of rotation of the system 10 plus further degrees offreedom to follow the movements of the operator allowed by the scapulargirdle, or more by the joint where the system 10 is applied.

In various preferred embodiments, as in the one illustrated in FIGS. 1-4, on its rear side, at the shoulder blades, the garment 12 carries apair of linear guides 14, preferably oriented in respective directionsand both inclined with respect to the frontal plane of the operator, tobe mutually divergent forwards, and regarding a horizontal plane, to bedivergent upwards, the guides substantially following the subspinatusplane of the scapula. Such linear guides 14 identify respective axes oftranslation Y1 and Y2. Mounted movably on each linear guide 14 is asliding-block assembly 16, which comprises an L-shaped supportingbracket 161, contained in the same plane of the respective linear guide14, and provided on its end with a joint 162, having two degrees offreedom, and configured for defining a first axis of rotation I1 and asecond axis of rotation I2 that are orthogonal to one another.

The bracket 161 is shaped so that the joint 162 is set substantially ina position corresponding to the rear part of the shoulder of theoperator.

The joint 162 connects the supporting bracket 161 to twomutually-articulated elements 18A and 18B, which identify the “assisted”axis of rotation of the system 10 described herein, designated by thereference I3.

The first element 18A is directly connected to the joint 162, regardingwhich it can turn about the first and second axes I1 and I2 referred toabove.

In various preferred embodiments, as in the one illustrated, the joint162 has an annular body that is rotatably mounted on a first pin 162A,which defines the first axis I1, and carries on itself two opposedradial pins 162B, which define the second axis I2. The first pin 162A isfixedly carried by the bracket 161, whereas the element 18A is rotatablymounted on the two pins 162B.

In various preferred embodiments, the joint 162 is set in a positioncorresponding to the gleno-humeral joint of the operator.

Even more preferably, the joint 162 is positioned to set the first axisI1 approximately orthogonal to the frontal plane of the operator in sucha way that rotation of the element 18A about the first axis I1 willsubstantially correspond to a movement of abduction/adduction of the armof the operator. The second axis I2 is arranged so rotation of theelement 18A about it will correspond substantially to a movement ofrotation of the shoulder. The element 18A extends in cantilever fashionfrom the joint 162 following a curvilinear profile to set its end 182opposite to the joint, in a position corresponding to the lateral partof the operator's shoulder. Mounted in an articulated way on this end182, about the axis of rotation I3, is the element 18B, which is fixedto a band 22 to be worn by the operator on his arm. The axis I3—in theresting condition illustrated in the figures—is a substantiallyhorizontal axis in the frontal plane of the operator. Any movement ofrotation of the arm of the operator with a component in the sagittalplane (orthogonal to the frontal plane), will determine a rotation ofthe element 18B regarding the element 18A about the axis of rotation I3.

The axis of rotation I3 constitutes the “assisted” axis of the system,at which axis the system generates a torque that assists the effortsmade by the operator. Given the orientation of the axis I3, theassistance generated can be exerted regarding a movement ofantero-projection (or projection forwards) of the arm or a movement inan opposite direction. The device that can generate this action ofassistance has a general constructional configuration given by:

-   -   a first gear member and a second gear member, which are        connected and are brought into relative motion about the        “assisted” axis of rotation because of the movement of the joint        of the operator's body, wherein the second gear member can        rotate about its own axis; and    -   an assembly equipped with one or more elastic mechanism, which        is prearranged for acting on the second gear member to impart on        the “assisted” axis of rotation a moment opposite to the        resistive moments;    -   wherein the first and second gear members and the “elastic”        assembly are mutually prearranged in such a way that, in at        least one pre-set position of the joint, the force exerted by        the aforesaid assembly on the second member is oriented in a        direction incident regarding the axis of rotation of the second        member.

FIGS. 5A and 5B illustrate two embodiments of this device.

Referring to FIG. 5A, the compensation device illustrated comprises afirst rotatable member 101, such as a first gear wheel, which is carriedby the end 182 of the element 18A, fixed thereon and having its own axisaligned with the axis of rotation I3. A second rotatable member 103,such as a second gear wheel, is rotatably mounted on the element 18B,about its own axis 14, parallel to the axis of rotation I3, and isarranged so it engages the first gear wheel 101. In operation, rotationof the element 18B about the axis of rotation I3 will hence determine amotion of rotation of the second gear wheel 103 about its own axis 14and a motion of revolution made by the first gear wheel itself about theaxis of rotation I3.

To return to the constructional configuration of the compensationdevice, this further comprises an elastic mechanism 105, preferablyequipped with a plurality of elastic mechanisms, which exerts a linearelastic force on an eccentric point of the second gear wheel 103. Invarious preferred embodiments, as in the one illustrated, the assembly105 has two opposed brackets 105A and 105B, the former fixed to thesecond gear wheel 103 on a fixing point 107 in an eccentric position,and the latter carried, instead, by the element 18B. Anchored to the twobrackets 105A and 105B are the respective opposite ends of an elasticelement of the elastic mechanism 105, which may be battery of helicalsprings, operating in tension. The overall action of the above springsdetermines a linear resultant force F applied on the fixing point 107(see FIGS. 6A-6C). As an alternative to the helical springs, the devicemay envisage elastic elements of some other type, for example one ormore elements made of elastomeric material, with the main advantage ofbeing lighter.

It should now be noted that the amplitude of the force F and its vectoron the fixing point 107 both vary as a function of the angle of rotationof the second gear wheel 103 about its own axis 14, and hence inultimate analysis as a function of the angle of rotation of the element18B about the axis of rotation I3; in the figures, this angle is denotedby the reference □ (FIG. 2 ).

For each angular position, the value of the force and the tangentialcomponent Ft of its vector will determine the degree of the assistanceprovided by the compensation device for the movement of forwardprojection of the arm.

FIGS. 6A-6C illustrate in a schematic way how the above quantities varyas the angle of rotation varies.

In the light of what has been described above, it will now be clear tothe person skilled in the sector that, by selecting the transmissionratio between the first and second gear wheels 101 and 103, it ispossible to establish different assistance curves.

FIG. 7 illustrates various examples of the curve of the assistancetorque, which is a function of the angle of rotation, that can besupplied by the system 10 for different transmission ratios of thegearing of the compensation device.

As seen in FIG. 7 , by increasing the transmission ratio, the maximum ofthe curve is shifted towards higher angles of rotation.

It is also possible to envisage the use of non-circular gear wheels,with variable transmission ratios, the purpose of this being to modifythe profile of the assistance curve in the perspective of obtaininggiven levels of performance. In various embodiments, there may beenvisaged a transmission ratio that increases as the angle of rotationincreases to obtain, regarding embodiments with constant transmissionratio, a reduction of the assisting torque for narrow angles (close tozero) and, instead, an increase of the assisting torque where there isthe maximum of the curve. FIG. 11 illustrates the assistance curve,designated by C′, generated by a compensation device equipped with gearwheels with increasing transmission ratio, and the assistance curve,designated by C″, generated, instead, by a device provided with elasticmeans that can define the same elastic force but have a gearing withconstant transmission ratio. FIG. 10 represents an example of thisdevice equipped with gear wheels with an increasing transmission ratio.Non-circular gear wheel 291 engages second gear wheel 292, generating asa result of the non-circular shape a variable transmission ratio. Firstand second opposed brackets 293A, 293B define therebetween an elasticmechanism 294, similar to previous embodiments, with first bracket 293Aattaching to the second gear wheel 292 at a fixing point 297.

The system can be easily prearranged for determining pre-set curvesoptimized for the specific requirements of the applications.

Regarding assistance to the movement of antero-projection of the arm,the system is suited for providing the best assistance if the maximumtorque available is generated at an angle of rotation of 90°, for thisis the most unfavorable condition regarding the gravitational momentacting on the arm itself.

As discussed above, the system is prearranged so the assistance torquesupplied is zero in at least one predefined position, a position thatcomes to constitute a neutral position of the system. In the embodimentillustrated, this neutral position corresponds to the position where theangle of rotation □ is zero, as is immediately visible from FIG. 7 ,where the curve represented has a zero value of assistance torque for anangle □ of 0°.

Referring to FIG. 6A, which represents the configuration of thecompensation device at that neutral position, it may be seen that forthis position the elastic force exerted by the elastic mechanism 105 onthe gear wheel 103 is oriented in a direction incident regarding theaxis of rotation of the gear wheel 103 itself. Incidentally, it shouldalso be noted that, in this condition, the direction that joins the twocenters of the gear wheels 101 and 103 and the direction of the vectorof the elastic force remain offset regarding one another.

Once again to render the system adaptable to the various applications,and likewise versatile, in various preferred embodiments, as in the oneillustrated, the elastic mechanism 105 is prearranged so the position ofthe bracket 105B regarding the opposed bracket 105A is adjustable, toallow the possibility for the operator of setting the pre-tensioningload of the springs. The elastic mechanism 105 envisages for thispurpose an adjustment device of a screw-operated type, which can haveeither a manual command, as in the embodiment illustrated having a knob,or else an electromechanical command provided by one or more actuatorswhich can be driven by a push button, the latter preferably being set ina position that can be reached easily by the operator even when wearingthe system. The possibility of adjustment enables the operator both toset the desired level of assistance and, possibly, to exclude italtogether.

With reference now to the embodiment of FIG. 5B, the compensation deviceillustrated is characterized in that it provides not a simple gearingwith two mutually coupling members, but rather an epicyclic gear trainprovided on the axis of rotation I3.

In various preferred embodiments, as in the one illustrated, the centralor “sun” gear 201 of the gear train is fixedly carried by the end 182 ofthe element 18A, with its own axis aligned to the axis of rotation I3.The crown wheel 203 is mounted fixed on the element 18B, in a positioncoaxial regarding the gear wheel 201, being rotatable about the axis I3itself.

A planetary-gear carrier 204 is rotatably mounted on the gear wheel 201,once again about the axis I3, carrying at the end of its arms the planetgears 206.

In operation, rotation of the element 18B about the axis of rotation I3will determine rotation of the crown wheel 203 and of the planetary-gearcarrier 204 about the axis I3, and the combined movement of rotation andrevolution of the planet gears 206 about their own axis of rotation andabout the axis I3.

In this embodiment, the elastic mechanism 105 is prearranged to exert alinear elastic force on an eccentric point 207 of the planetary-gearcarrier 204; its bracket 105A is fixed on one of the arms of the latter.

As compared to the compensation device of FIG. 5A, the device justdescribed is characterized in that it presents smaller overalldimensions and a lower weight while providing the same levels ofperformance and the same structural parameters.

The operating principle of this device is the same as the one mentionedabove referring to the embodiment of FIG. 5A.

Also, the amplitude of the elastic force generated by the elasticmechanism 105 and its vector on the point of application 207 vary as afunction of the angle of rotation of the gear wheel 203 about the axisof rotation I3 and hence as a function of the angle of rotation.

For each angular position, the value of the above force and thetangential component Ft of its vector will determine the amount of theassistance provided by the device regarding the movement of forwardprojection of the arm.

In addition, also in this embodiment, the device is prearranged so theassistance torque supplied is zero at at least one neutral position ofthe system. This will correspond to a position where the elastic forceexerted by the elastic mechanism 105 on the planetary-gear carrier 204is oriented in a direction incident regarding the axis of rotation I3.

Once again referring to the compensation device equipped with anepicyclic gear train, alternative embodiments may envisage that thecrown wheel 203 is fixed to the element 18A and, instead, the centralgear wheel 201 is fixed to the element 18B, according to a configurationopposite to the one illustrated.

With reference now to the axes of movement Y1, Y2, I1, and I2, thesystem does not exert any assistance torque about these axes, but simplythanks to these axes it can follow the joint movements out of thesagittal plane of the operator. The operator is hence not constrained inany specific posture or position and can, instead, assume the posturethat is most comfortable for himself for the task to be carried out, andin the position chosen will receive the assistance to the effortrequired, about the axis I3.

It should again be noted that the linear guide 14, besides assisting thepossible movements of the shoulder with a component along the axes Y1,Y2, also enables the system to adapt to the build of the operator, thesliding-block assemblies 16 moving away from one another or towards oneanother according to the breadth of shoulders. The garment 12 mayenvisage fixing members such as belts, hook and loop fasteners, andetc., for adjustable closing thereof.

As anticipated above, the principles set forth can be identicallyreproduced to provide a system of assistance designed for use for otherjoint groups or other joints, for the hip joint or alternatively theknee joint.

FIG. 8 illustrates an example of a system of assistance for the hipjoint. Here, the assistance supplied is exerted for the movement ofbending of the thigh relative to the pelvis, or else to the movement ofbending of the torso on the pelvis, according to the task carried out bythe operator.

The neutral position discussed above corresponds in this case to theupright position of the operator.

The axes of movement of the above system and the compensation devicecorrespond identically to those of the system described previously,clearly transposed onto the hip joint.

What changes is basically the garment worn by the operator, which in thesystem of FIG. 8 is constituted by a belt that girds the pelvis, whichcarries a linear guide 254 and two articulation elements 218A, and bytwo bands 272 worn on the thighs, to which the two articulation elements218B are constrained. In particular, the embodiment of FIG. 8 shows asystem 250 comprising a garment 252 and a mobile frame including a joint282 arranged to adapt to an operator's dimensions and movements. Joint282 comprises a rotatable annular body 264 that is rotatably mounted onthe mobile frame and facilitates adduction and abduction of theoperator's legs. System 250 further comprises a rod 266 facilitatinginward and outward rotations of the hip, thus providing two degrees offreedom that are orthogonal to one another, as in thepreviously-described embodiment.

System 250 also comprises a compensation device 285 comprising anelastic mechanism as provided in the previously-described embodiment andconfigured to aid the operator in degrees of maintaining of uprightposition.

FIG. 9 illustrates, instead, an example of system 280 of assistance forthe knee joint. Here, the wearable garment comprises two bands 260, 268,one worn at the level of the thigh and the other worn at the level ofthe calf. The system 280 likewise comprises a compensation device 290that aids the operator in maintaining a desired degree of flexion andextension of the leg.

FIG. 12 shows another embodiment of a compensation device 300 based on aspring-based mechanism generating torque proportional to an elevationangle of a user's arm, as in foregoing embodiments. As with theforegoing embodiments the compensation device is arranged to generatetorque proportional to the elevation angle of a user's arm.Advantageously, this embodiment provides a pretension system thatenables a user to adjust the extent of the pretension in a simplifiedand quick manner, with a plurality of predetermined settings.

Referring to the compensation device embodiments of FIGS. 5A and 5B, atension regulation mechanism 150 is located at a second or lower end ofthe compensation device 100, 200. The tension regulation mechanism 150comprises an interface mechanism 152, such as a dial 152, arranged toactuate a rod or screw mechanism 154 to lengthen or shorten the secondbracket 105B relative to the first bracket 105A. A mount 156 for thesecond bracket 105B may be connected to and movable according todisplacement of the rod 154 according to adjustment of the dial 152.Tension is adjusted by setting the distance between the two extremitiesof the elastic mechanism 105, varying a distance between first andsecond ends of the elastic mechanism 105.

Turning to FIG. 12 , the compensation device 300 has a housing 302 inwhich features of the compensation device 300 are contained. Thesefeatures of the compensation device 300 include a rotational assembly304 adapted to connect to the articulated element 18A, an elasticmechanism 306 coupled to the gear assembly 304, and a tension regulationdevice 308 connected to and having a cam assembly 310 configured tomodify tension in the elastic mechanism 306.

The gear assembly 304 includes a first rotatable member or shoulder gear312 having a geared outer periphery 313 that meshes with a geared outerperiphery 316 belonging to a second rotatable member or spring gear 314.The first rotatable member 312 is brought into relative motion about theaxis of rotation I3 because of the movement of the joint of theoperator's body, wherein the second rotatable member 314 can rotateabout its own axis.

The second rotatable member 314 is coupled by a first bracket 318 to theelastic mechanism 306. The elastic mechanism 306 is shown as havingfirst and second elastic elements 324, 326 in the form of helicalsprings, and secure to the first bracket 318 by at least one first mount320, 322. The elastic mechanism 306 is arranged to exert a linear forceon an eccentric point 323 on the first bracket 318.

The elastic mechanism 306 connects to a second bracket 332 by at leastone second mount 328, 330. The second bracket 332 connects to theregulation device 308, such as with a central connection 336 on a slider334.

The cam assembly 310 has at least one cam 338, 340 that is selectivelyengageable with a positional holder 342, such as a pin, extending fromthe slider 334. The at least one cam 338, 340 has a surface 341 definingat least two equilibrium points 350 defining predetermined tensionsettings of the elastic mechanism 306. The at least one cam 338, 340 maydefine first and second cams 338, 340 extending on first and secondopposed sides of the slider 334 for engagement with the pin 342 that maylikewise extend from opposed sides of the slider 334.

As represented in FIGS. 12 and 13B, the cam assembly 310 has aninterface mechanism 344 for permitting a user to regulate the tension ofthe elastic mechanism 306 by adjusting the position of the cam assembly310. The interface mechanism 344 may including a coupling part 346securing to a boss 347 formed or connected to the at least one cam 338,340. The interface mechanism 344 may further define a keyhole 348 forpermitting insertion of a tool and regulation of the cam assembly 310 byturning the at least one cam 338, 340 to one of the predeterminedsettings.

FIG. 13A illustrates the housing 302, or otherwise disposed proximatethe interface mechanism 344, as having indicia 349, such as in aregulation scale, for designating the predetermined settings afforded bythe cam assembly 310. The keyhole 348 may be used in combination with astandard hexagonal key or customized tool to regulate the cam assembly310.

FIG. 14A illustrates the first cam 338 as having depressions 350A-350Gthat create equilibrium points corresponding to the different assistancelevels for the compensation device 300. Both the first and second cams338, 340 may be rotationally connected to one another and adjust axiallysimultaneously, to engage the pin 342 at the same correspondingdepression. Each depression 350A-350G sets a different distance betweenthe cam axis A and the pin 342, as evidenced by the radial lines352A-352G each having a different radius from another, and therefore seta different distance between the two spring extremities, such asmeasured by the first and second brackets. This arrangement causes achange of the elastic mechanism and offers different exoskeletonassistance.

FIG. 14A generally shows how the pin 342 is forced against the first cam338 by tension in the elastic mechanism 306, and sits in equilibrium inthe first cam depression 350A. Rotation of the cam assembly 310 requiresan external torque to make the pin ‘climb’ out of the depression 350A.FIG. 14B shows how torque is applied to cam assembly 310 by theinterface mechanism 344 which turns the cam assembly 310. The first cam338 rotates until the pin 342 reaches the top of the of a regulationstep 352A. As the first cam 338 is rotated, the pin 342 starts its fallinto the second depression 350B. No more torque is needed. Once the pin342 is in the second depression 350B, it is in equilibrium and will notrotate again unless an external torque is applied.

It will be understood that a torque must be applied to the interfacemechanism 344 to force the at least one cam 338, 340 to leave anequilibrium point 350 and reach a different equilibrium stance at one ofthe other equilibrium points, as depicted in FIGS. 16A and 16B. FIG. 15Ashows the pin 342 located in a third depression 350C, with radius of354C from the axis A. FIG. 15B shows the pin 342 located in a seventhdepression 350G, with a radius of 354G from the axis A. This happensbecause, in each working condition, at each regulation level, theelastic mechanism 306 is always tensioned and then the regulation device308 is always forced against the cam assembly 310, creating a torqueprofile characterized by a sequence of ‘valleys’ (equilibriumpoints/depressions) and ‘hills’ (regulation steps).

FIG. 16A exemplifies the relationship of the torque interface mechanismon the cam rotation angle. The plots above the torque 0, representpositive torque needed to move the cam mechanism over a regulation stepfrom equilibrium point (for example from equilibrium point 350A toequilibrium point 350B). The plots below the torque 0, representnegative torque used to move the cam mechanism past the regulation stepinto next equilibrium point.

FIG. 16B exemplifies the elastic potential energy from one equilibriumpoint according to the cam rotational angle to another equilibriumpoint. This may be from equilibrium point 350A to equilibrium point350B.

Potential energy is accumulated or spent as the cam moves up or down‘hills’ between adjacent stable equilibrium points/‘valleys’. Whenmoving either upward or downward (i.e., when either accumulating orspending potential energy), the cam first encounters an area requiringan input of torque in order to overcome the local minimum of potentialenergy, then the cam encounters an area in which the cam may ‘twitch’into the adjacent position by ‘rolling down’ the slope into the adjacentstable equilibrium point/‘valley’.

As seen in FIGS. 16A-16B, this is true even when the cam is net spendingpotential energy: the cam must first overcome the local minimum ofpotential energy by reaching a local maximum or ‘hill’ through the inputof torque, and then may ‘twitch’ to come to rest in the adjacent‘valley’ with an overall loss of potential energy. Input torque is alsorequired to move the cam into an adjacent setting with a net gain inpotential energy: as input torque moves the cam to an adjacent the cammay then twitch to settle into the adjacent ‘valley’ with a higherpotential energy than the previous ‘valley’. This arrangement isadvantageous as it requires a deliberate selection of the cam setting bythe operator, rather than allowing the cam to spontaneously oraccidentally switch between settings.

Without prejudice to the principle of the invention, the details ofconstruction and the embodiments may vary, even significantly, regardingwhat has been illustrated purely by way of non-limiting example, withoutdeparting from the scope of the disclosure, as this is defined by theannexed claims.

The embodiments described herein provide a system for assisting anoperator in exerting efforts that provides improved ergonomics and easeof use, particularly through the operation of the compensation device toprovide adjustable and discrete amounts of torque to aid an operator inperforming certain effortful motions.

1-20. (canceled)
 21. A compensation device in a system for assisting anoperator in exerting efforts by a joint of the operator, thecompensation device comprising: a first rotatable member arranged torotate about a first axis of rotation; a second rotatable memberarranged to rotate about a second axis of rotation, wherein the firstrotatable member is connected to the second rotatable member; an elasticmechanism having at least one elastic element arranged for exerting anelastic force on the second rotatable member to impart on the first axisof rotation a moment opposite to resistive moments acting on a joint ofthe operator; wherein the first and second rotatable members and theelastic mechanism are arranged in at least one pre-set position, suchthat a force exerted by the elastic mechanism on the second rotatablemember is oriented in a direction incident with respect to the secondaxis of rotation of the second rotatable member; wherein thecompensation device includes an epicyclic gear train mounted at thefirst axis of rotation including a crown wheel or central gear wheeldefining the first rotatable member; and wherein the second rotatablemember includes a planetary-gear carrier wherein the elastic mechanismengages the planetary-gear carrier, and is arranged to exert a linearforce on an eccentric point thereof.
 22. The compensation deviceaccording to claim 21, wherein the at least one elastic elementcomprises at least one spring anchored having a first end anchored tothe eccentric point of the second rotatable member.
 23. The compensationdevice according to claim 22, wherein a position of the second end ofthe elastic mechanism with respect to the first end is adjustable forsetting pre-tensioning of the at least one spring.
 24. The compensationdevice according to claim 21, further comprising a tension regulationdevice connected and adapted to regulate tension in the elasticmechanism.
 25. The compensation device according to claim 24, whereinthe tension regulation device is arranged for pre-tensioning the elasticmechanism at a plurality of discrete tension settings and placing thepre-tension at one of the plurality of discrete tension settings. 26.The compensation device according to claim 24, wherein the tensionregulation device includes a cam assembly for adjusting the elasticmechanism at a plurality of discrete tension settings.
 27. Thecompensation device according to claim 24, wherein the tensionregulation device further includes an interface mechanism forselectively adjusting the compensation device.
 28. The compensationdevice according to claim 21, wherein an amplitude of the elastic forcegenerated by the elastic mechanism varies as a function of an angle ofrotation of the crown wheel.
 29. The compensation device according toclaim 21, wherein the compensation device is arranged so that thecompensation device is provided with an assistance torque at zero in atleast one neutral position of the system.
 30. The compensation deviceaccording to claim 29, wherein the at least one neutral position of thesystem includes a position wherein the elastic force exerted by theelastic mechanism on the planetary-gear carrier is oriented in adirection incident to the first axis of rotation.
 31. The compensationdevice according to claim 21, wherein the first and second rotatablemembers have a transmission ratio that is variable as a function of anangle of rotation about the first axis of rotation.
 32. The compensationdevice according to claim 21, wherein the elastic mechanism includes afirst bracket opposite to a second bracket, the first bracket secured tothe second rotatable member on the eccentric point in an eccentricposition.
 33. The compensation device according to claim 32, wherein theat least one elastic element includes at least one spring secured toopposed ends of the first and second brackets.
 34. The compensationdevice according to claim 32, wherein the first and the second bracketsare secured to first and second mounting elements separately articulablerelative to one another.
 35. The compensation device according to claim34, wherein the crown wheel is fixed to the first mounting element andthe central gear wheel is fixed to the second mounting element.